From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Pi-Hsun Shih <pihsun@chromium.org>,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 3.18 10/10] include/linux/swap.h: use offsetof() instead of custom __swapoffset macro
Date: Fri, 29 Mar 2019 21:32:27 -0400 [thread overview]
Message-ID: <20190330013227.1365-10-sashal@kernel.org> (raw)
In-Reply-To: <20190330013227.1365-1-sashal@kernel.org>
From: Pi-Hsun Shih <pihsun@chromium.org>
[ Upstream commit a4046c06be50a4f01d435aa7fe57514818e6cc82 ]
Use offsetof() to calculate offset of a field to take advantage of
compiler built-in version when possible, and avoid UBSAN warning when
compiling with Clang:
UBSAN: Undefined behaviour in mm/swapfile.c:3010:38
member access within null pointer of type 'union swap_header'
CPU: 6 PID: 1833 Comm: swapon Tainted: G S 4.19.23 #43
Call trace:
dump_backtrace+0x0/0x194
show_stack+0x20/0x2c
__dump_stack+0x20/0x28
dump_stack+0x70/0x94
ubsan_epilogue+0x14/0x44
ubsan_type_mismatch_common+0xf4/0xfc
__ubsan_handle_type_mismatch_v1+0x34/0x54
__se_sys_swapon+0x654/0x1084
__arm64_sys_swapon+0x1c/0x24
el0_svc_common+0xa8/0x150
el0_svc_compat_handler+0x2c/0x38
el0_svc_compat+0x8/0x18
Link: http://lkml.kernel.org/r/20190312081902.223764-1-pihsun@chromium.org
Signed-off-by: Pi-Hsun Shih <pihsun@chromium.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/linux/swap.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 1dc0e886227d..054cddb52482 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -143,9 +143,9 @@ struct swap_extent {
/*
* Max bad pages in the new format..
*/
-#define __swapoffset(x) ((unsigned long)&((union swap_header *)0)->x)
#define MAX_SWAP_BADPAGES \
- ((__swapoffset(magic.magic) - __swapoffset(info.badpages)) / sizeof(int))
+ ((offsetof(union swap_header, magic.magic) - \
+ offsetof(union swap_header, info.badpages)) / sizeof(int))
enum {
SWP_USED = (1 << 0), /* is slot in swap_info[] used? */
--
2.19.1
prev parent reply other threads:[~2019-03-30 1:32 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-30 1:32 [PATCH AUTOSEL 3.18 01/10] rsi: improve kernel thread handling to fix kernel panic Sasha Levin
2019-03-30 1:32 ` [PATCH AUTOSEL 3.18 02/10] 9p: do not trust pdu content for stat item size Sasha Levin
2019-03-30 1:32 ` [PATCH AUTOSEL 3.18 03/10] 9p locks: add mount option for lock retry interval Sasha Levin
2019-03-30 1:32 ` [PATCH AUTOSEL 3.18 04/10] serial: uartps: console_setup() can't be placed to init section Sasha Levin
2019-03-30 1:32 ` [PATCH AUTOSEL 3.18 05/10] ARM: samsung: Limit SAMSUNG_PM_CHECK config option to non-Exynos platforms Sasha Levin
2019-03-30 1:32 ` [PATCH AUTOSEL 3.18 06/10] ACPI / SBS: Fix GPE storm on recent MacBookPro's Sasha Levin
2019-03-30 1:32 ` [PATCH AUTOSEL 3.18 07/10] iommu/dmar: Fix buffer overflow during PCI bus notification Sasha Levin
2019-03-30 1:32 ` [PATCH AUTOSEL 3.18 08/10] appletalk: Fix use-after-free in atalk_proc_exit Sasha Levin
2019-03-30 1:32 ` [PATCH AUTOSEL 3.18 09/10] lib/div64.c: off by one in shift Sasha Levin
2019-03-30 1:32 ` Sasha Levin [this message]
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